A reconfigurable IC for wireless monitoring of chemical or electrical neural activity

A reconfigurable integrated circuit for single-channel wireless monitoring of chemical or electrical neural activity is described. It can perform both amperometry and fast-scan cyclic voltammetry (FSCV) when configured for neurochemical sensing, and can record extracellular action potentials as well as local field potentials (LFPs) when configured for electrophysiological studies. The chip architecture employs a third-order ΔΣ modulator (ΔΣM) and a frequency-shift-keyed (FSK) transmitter operating near 433MHz. It also incorporates a programmable arbitrary waveform generator for FSCV measurements. The chip is fabricated using the AMI 0.5μm 2P/3M n-well CMOS process, and achieves a measured current resolution of 94.1pA rms in a 5-kHz bandwidth for 300-V/s FSCV and an input-referred noise voltage of 4.69μV rms in a bandwidth of 1.1-5kHz. The modulator core, FSCV waveform generator, and RF transmitter draw ∼28μA, ∼40μA, and ∼400μA from a 2.5-V power supply, respectively.